Add `test-platform` fixture for ixmp4 tests #1327

	# This workflow installs the package and builds the docs
	# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions

	name: build the docs

	on:
	push:
	branches: [ 'main' ]
	pull_request:
	branches: [ '**' ]

	jobs:
	docs:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4

	- name: Set up Python
	id: setup-python
	uses: actions/setup-python@v5
	with:
	python-version: '3.10'

	- name: Install Pandoc
	uses: r-lib/actions/setup-pandoc@v2

	#------------------------------
	# install & configure poetry
	#------------------------------
	- name: Install Poetry
	uses: snok/install-poetry@v1
	with:
	virtualenvs-create: true
	virtualenvs-in-project: true
	installer-parallel: true

	#------------------------------------
	# load cached venv if cache exists
	#------------------------------------
	- name: Load cached venv
	id: cached-poetry-dependencies
	uses: actions/cache@v4
	with:
	path: .venv
	key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}

	#------------------------
	# install root project
	#------------------------
	- name: Install library
	run: poetry install --no-interaction --extras "docs optional_plotting tutorials"

	- name: Build the docs
	run: poetry run make --directory=docs html

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